Eggs, peanutbutter, and oatmeal. Also, full fat milk, yogurt (greek is best but whatever you can get him to eat) and cheese. My LO loved full fat greek yogurt with smashed fruit mixed in. I did use vanilla greek yogurt instead of original because she hated the original, and I'd rather her have full fat vanilla greek yogurt than something else.
Thank you guys!
Peanut butter snacks Bananas Mashed potatoes Any flavored Rice he likes Stringed Cheese Yogurt Avocado is high in fats
Add avocado oil to your baby’s food (like a teaspoon into his meal or coat it in a thin layer of the oil), high in fats and an easy way to sneak in extra calories!
Dairy. I've heard it be suggested to add double cream to other foods to increase the calorie intake.